Cleaning of manufactured jewelry



CROSS REFERENCE EXAMINER Patented Oct. 7, 1952 UNITED STATES PATENT OFFICE CLEANING OF MANUFACTURED JEWELRY PARTS John V. Lorea and Thomas F. ORourke, Providence, R. I.

No Drawing. Application November 8, 1945, Serial No. 627,520

6 Claims. (Cl. 1342) even from hidden surfaces, and leaves the metal in its natural state, requiring only a glossing to bring out its true color.

A further object of the invention is to provide a cleaning method which permits basket cleaning Either sodium or potassium cyanide may be used, the cyanide preferably being in the form of a cyanide egg, and the weight being from ounces up to 10 ounces. The range of the hydrogen peroxide is from 600 cc. to 800 co. in the solution specified.

The cleaned work is then dipped in a standard cyanide solution, after an initial rinsing to conserve the cyanide, and rinsed; the standard cyanide solution contains about four ounces of sodium cyanide to a gallon of water. The rinsed work is then immersed in a bright dip solution having the following proportions for a four gallon volume:

and eliminates need for stringing or otherwise Solution No. 2 separating the work.

It has been found desirable to provide an im- Water 3% gallons proved non-acid bright dip which is particularly Sodium perborate 4ounces by wei h suitable for cleaning jewelry items of the gold Sodium cyanide 2ounces by weight filled and karat gold type. Such jewelry items have heretofore been cleaned by stringing the ing, the jewelry items are easily mutilated by careless or deliberate over-stripping, and it has heretofore been customary to provid an increased weight of metal in order to ensure that the finished product will come up to selling weight.

We have found it possible to utilize a simple and relatively inexpensive cleaning process which removes all oxidation from the jewelry items, which may be placed in baskets without stringing, with no stripping action on the metal itself.

To accomplish this advantageous result, we first pickle the work to lift the scale; we then immerse the work, which is heaped in standard open-work baskets, in a tank containing a cleaning solution having the following proportions for a four gallon volume:-

One-quarter of the sodium cyanide is permitted to dissolve before the dip, and the solution is used cold. The Work is kept in the solution, and agitated slightly by hand or mechanically, until the oxidation is removed. For gold-filled or karat gold, the time required is about five minutes; for brass, the time is about ten minutes.

The chemicals for Solution No. 2 are permitted to dissolve first and the solution is kept hot, preferably at a temperature of about or higher..

The cyanide treated work is dipped in Solution No. 2 to brighten the previously treated work, and the brightened work is removed and rinsed in water. The perborate may range from 3 ounces to 4 ounces, and the cyanide from 2 to 3 ounces, the cyanide being dissolved first.

The above described chemical treatment is particularly advantageous for gold-filled and karat gold jewelry items, as it eliminates the present use of a reverse current potassium cyanide solution which requires stringing of the separate pieces of work, and does not require a skilled operator who has to control the solution. Even with skilled operation, oxidation was not removed evenly by the customary process, as the closer an article of work is to the cathode the more metal is removed therefrom; it has been impossible heretofore to remove the oxidation evenly from all the pieces being treated. With the above described pro-- cedure the essential effect of Solution No. 1 is to substantially completely remove all oxidation,

. Solution 1 45 both exposed and hidden, without attacking the Water 3 /2 gallons metal, leaving the metal in its natural state, and Sodium cyanide 6 ounces by W ight Solution No. 2 brightens the metal so that the 33% hydrogen peroxide 700 cc. true color is quickly brought out by a glossing operation. Solution No. 2 should not be used for treating brass parts; the brass parts are bright when removed from Solution No. 1.

The above described chemical treatment is particularly suitable for cleaning gold-filled and karat gold jewelry parts; it is also applicable to other metal parts made of brass, brass alloys.

silver, white metal and the like, and has been found of advantage for aluminum parts.

The term cyanide salt" as used in the claims signifies sodium or potassium cyanide.

Although we have described a specific chemical treatment for cleaning metal parts, using specific proportions of chemicals in solution which we have found critical for the results desired, the invention is not limited to the specific method and proportions shown, and may be changed to accomplish the cleaning of different types and kinds 01' metal, without departing from the spirit and the scope of the invention as defined in the appended claims.

We claim:

I. The method or chemically cleaning metal Jewelry parts made of gold-filled, karat gold, silver, brass, brass alloys and the like to remove oxidation, comprising the steps of immersing the jewelry parts in a solution containing when prepared five to ten ounces by weight of alkali metal cyanide and hydrogen peroxide equivalent to 600 to 800 cc. of 33% solution per 3 gallons of water, and agitating the Jewelry parts while immersed, the time of immersion and agitation being not more than fifteen minutes.

2. The method of chemically cleaning metal jewelry parts made of gold-filled, karat gold, silver, brass, brass alloys and the like to remove oxidation, comprising the steps of immersing the jewelry parts in a solution containing when prepared .five to ten ounces by weight of sodium cyanide and hydrogen peroxide equivalent to 600 to 800 cc. of 33% solution per 3 gallons of water, and agitating the jewelry parts while immersed, the time of immersion and agitation being not more than fifteen minutes.

3. The method of chemically cleaning metal jewelry parts made of gold-filled, karat gold, silver, brass, brass alloys and the like to remove oxidation, comprising the steps of immersing the jewelry parts in a solution containing when prepared five to ten ounces by weight of potas-- sium cyanide and hydrogen peroxide equivalent to 600 to 800 cc. of 33% solution per 3 /2 gallons of water, and agitating the jewelry parts while immersed, the time of immersion and agitation being not-more than fifteen minutes.

4. The method of chemically cleaning metal jewelry parts made of gold-filled, karat gold, silver, brass, brass alloys and the like to remove oxidation, comprising the steps or immersing the jewelry parts in a solution containing when prepared five to ten ounces by weight of alkali metal cyanide and hydrogen peroxide equivalent-to 600 tc 800 cc. of 33% solution per 3% 1 4 gallons of water, and agitating the jewelry parts while immersed, the time of immersion and agitation being not more than fifteen minutes, dipping the cleaned parts in a solution of 4 ounces of sodium cyanide in one gallon of water, and rinsing.

5. The method of chemically cleaning metal jewelry parts made of gold-filled, karat gold, silver, brass, brass alloys and the like to remove oxidation, comprising the steps of immersing the jewelry parts in a solution containing when prepared five to ten ounces by Weight of sodium cyanide and hydrogen peroxide equivalent to 600 to 800 cc. of 33% solution per 3 gallons of water, and agitating the jewelry parts while immersed, the time of immersion and agitation being not more than fifteen minutes, dipping the cleaned parts in a solution of 4 ounces of sodium cyanide in one gallon of water, and rinsing.

6. The method of chemically cleaning metal jewelry parts made of gold-filled, karat gold, silver, brass, brass alloys and the like to remove oxidation, comprising the steps of immersing the jewelry parts in a solution containing when prepared five to ten ounces by weight of potassium cyanide and hydrogen peroxide equivalent to 600 to 800 cc. of 33% solution per 3 gallons of water, and agitating the jewelry parts while immersed, the time of immersion and agitation being not more than fifteen minutes, dipping the cleaned parts in a solution of 4 ounces of sodium cyanide in one gallon of water, and rinsing.

JOHN V. LOREA. THOMAS F. O'ROURKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 171,035 Monnier Dec. 14, 1875 699,108 Hunt Apr. 19, 1902 1,917,489 Bizzoni July 11, 1933 1,939,241 Taylor Dec. 12, 1933 2,108,604 Mason Feb. 15, 1938 2,160,391 Reichert May 30, 1989 2,166,954 Kaufimann July 25, 1939 2,353,026 Gilbert July 4, 1944 2,420,262 Navaretta May 6, I947 OTHER REFERENCES Mellon-"Modern Inorganic Chemistry" page 662, Longmans, Green and Co., New York,'1939. (Copy in Div. 27) 

1. THE METHOD OF CHEMICALLY CLEANING METAL JEWELRY PARTS MADE OF GOLD-FILLED, KARAT GOLD, SILVER, BRASS, ALLOYS AND THE LIKE TO REMOVE OXIDATION, COMPRISING THE STEPS OF IMMERSING THE JEWELRY PARTS IN A SOLUTION CONTAINING WHEN PREPARED FIVE TO TEN OUNCES BY WEIGHT OF ALKALI METAL CYANIDE AND HYDROGEN, PEROXIDE EQUIVALENT TO 500 TO 300 CC. OF 33% SOLUTION PER 3 1/2 GALLONS OF WATER, AND AGITATING THE JEWELRY PARTS WHILE IMMERSED, THE TIME OF IMMERSION AND AGITATION BEING NOT MORE THAN FIFTEEN MINUTES. 